Railway wheel and axle assembly

ABSTRACT

A flanged wheel and axle assembly of the type having a bearing enclosed against a collar on the axle by a pressure plate system, is provided with two pressure plates, one mounted axially behind the other, the plates being in mutual contact only in a central zone, the plate closest to the wheel resting directly or indirectly against the bearing structure, and the second plate being drawn towards the end of the axle by drawing means extending through the first plate. A sleeve preferably is provided on the axle between the pressure plate system and the bearing structure; the bearing structure preferably comprises spaced cylindrical and adjustable bearing; the drawing means preferably comprises three or more bolts positioned symmetrically about the central zone of contact; and the assembly forms part of a railway car subjected to high loads.

United States Patent Van Wierst et al.

[ 1 RAILWAY WHEEL AND AXLE ASSEMBLY [72] Inventors: Wilhelmus LambertusVan Wierst,

Santpoort; Pieter Jozef Marie Paffen, Alkmaar, both of Netherlands [73]Assignee: Koninklijke Nederlandsche Hoogovens En Staalfabrieken N.V.,Ijmuiden, Netherlands [22] Filed: Oct. 19, 1970 [21] Appl. No.: 82,002

[30] Foreign Application Priority Data Oct. 27, 1969 Netherlands..69l6l78 [52] US. Cl. ..295/36 R, 151/54, 295/36 A, 295/44, 295/46,308/ 180 [51] Int. Cl ..B60b 37/10, Fl6b 39/02, Fl6c 37/10 [58] Field ofSearch ..295/36 R, 36 A, 44, 45, 46, 295/49; 308/180; 151/54 [56]References Cited UNITED STATES PATENTS 760,505 5/1904 Wilcox ..295/36 R1,574,23l 2/1926 Carroll ..295/36 A [451 Oct. 10, 1972 10/1957 Milligeret al. ..308/180 8/1970 l-leggy et al. ..295/36 R 57 ABSTRACT A flangedwheel and axle assembly of the type having a bearing enclosed against acollar on the axle by a pressure plate system, is provided with twopressure plates, one mounted axially behind the other, the plates beingin mutual contact only in a central zone, the plate closest to the wheelresting directly or indirectly against the bearing structure, and thesecond plate being drawn towards the end of the axle by drawing meansextending through the first plate. A sleeve preferably is provided onthe axle between the pressure plate system and the bearing structure;the bearing structure preferably comprises spaced cylindrical andadjustable bearing; the drawing means preferably comprises three or morebolts positioned symmetrically about the central zone of contact; and

the assembly forms part of a railway car subjected to high loads.

5 Claims, 2 Drawing Figures PATENTEDnm 101972 3,697.1 l9

W/Lf/ELMUJ L K W/ERJT X PIETER J17, PAH-0 INVENTORS ATTORNEY RAILWAYWHEEL AND AXLE ASSEMBLY This invention relates to a structure comprisinga shaft or axle and a flanged wheel rotatably supported thereon,particularly a railwheel for extremely high loads per shaft, in which abearing structure of the wheel is enclosed against a collar on the shaftor axle by a pressure plate system secured to the end face of the shaftor axle. When using railway cars for industrial applications there is anincreasing tendency to apply higher loads per shaft. This isparticularly true for railway cars for internal transport in factories,for instance for moving in railroad yards of metallurgical factories.Examples of railroad cars for which this is the case ate the pig ironmixing cars and the so-called casting cars for conveying cast steelingots.

As a rule in such cars the wheels are secured on the shafts or axles andthus the latter are made rotatable. A modern development is to mount thewheels freely rotatable on stationary shafts or axles. An advantage ofthis structure consists in the fact that the wheels are free to take uptheir own speed in curves, so that the wear between wheel and rail,particularly at these very high shaft loads, is restricted.

As a result of the stability of the cars which often is required, theweight to be taken up is usually transitted to the axles or shafts inzones outboard of the wheels. For this purpose the shafts oraxles areextended to zones past the outer face of the wheel. This gives a problemhow to enclose and keep in place the wheel and the hearing from the freeend of the shaft or axle. It would be possible to mount a sleeve overthe end of the shaft or axle between the wheel and the end face and toenclose and keep in place this sleeve by the pressure plate system,which sleeve in its turn keeps the wheel and the bearing in the correctposition.

However, this structure could entrain the disadvantage that in the zonesof the very highly loaded axle ends and the sleeves mounted on them,such axle ends and such sleeves deform to such an extent that thepressure plate system is locally subjected to very high stresses.Particularly if the pressure plate system is secured by a number ofbolts onto the end face of the axle end, such bolts will be loaded quitedifferently mutually. This often gives rise to rupture of these bolts orof the pressure plate system. Such rupture of bolts may be the cause ofdamage to cars.

This invention aims at obtaining a structure in which this danger doesnot arise. In particular the structure according to the invention aimsat obtaining a more uniform loading and stressing of the pressure platesystem.

In view thereof this invention consists in embodying a structure asgiven in the preamble above in such a way that the pressure plate systemconsists of two plates, one mounted axially behind the other, whichplates are only in mutual contact in the central zone, the first platebeing closest to the wheel and applying pressure directly or indirectlyagainst the bearing structure and the second plate being drawn towardsthe end of the shaft or axle by means of bolts extending through thefirst plate. More especially the invention consists in that between thewheel and the end face of the shaft or axle end a sleeve is slid overthis end, which is kept in place by the pressure plate system betweenthe first plate and the bearing system. As a result of the fact that thetwo plates are in contact with one another only in peared that thispossibility of movement is sufficient to take up the discontinuities inview of the non-uniform deformation of the axle or shaft end and of thesleeve. Thereby the bolts will be loaded more uniformly, so that toohigh loads are avoided.

Although the effect of the new structure is already noticeable if thereis a rather arbitrary distribution of the bolts over the surface of thepressure plates, the best results are obtained if the bolts arepositioned on an imaginary circle, and in particular if only three boltsare positioned at the same distance from the axle center and at the samemutual angles, so according to an equilateral triangle.

In this last embodiment it is possible, independent on the discontinuityof the deformation of axle end and sleeve to obtain a substantiallyuniform distribution of forces between the three bolts.

In this structure the two pressure plates can more or less tilt (turn orwobble) with respect to each other about the point or small zone ofcontact in the central part. In order to make the stability of thestructure as high as possible is its preferable to take additionalmeasures by which the non-uniformity of the deformation of the axle endand of the sleeve are restricted to minimum values. It has appeared thatthis is obtainable by a good choice and mutual positioning of thebearings, by which the wheel is supported on the axle, or shaft.According to the invention in this respect a structure is preferable inwhich the wheel is rotatable around the shaft by means of a first and asecond bearing, the first bearing being a spherical or other adjustableroll bearing, positioned in the plane through the rim of the wheel, thesecond bearing being a cylindrical roll bearing at a distance from thefist bearing. This choice and positioning of the bearings moreover hasthe advantage that the forces in the bearings may be calculatedaccurately, the calculated horizontal forces on the wheel being taken upby the spherical roll bearing and the calculated vertical forces beingtaken up by both bearings simultaneously. Thanks to this possibility tocalculate the bearings exactly it is also possible to choose bearingshaving the same efficient life time during operation of the railroadcar.

This invention will now be explained in more detail with reference tothe enclosed drawing. In said drawmg:

FIG. 1 shows the structure in axial section, and

FIG. 2 shows a detail of FIG. 1 in end view.

In FIG. 1 reference numeral 1 indicates a rail wheel in axial section.This flanged wheel is rotatable about shaft or axle 2, which is providedwith collar or shoulder 3 spaced from and facing the outboard end of theshaft 2. Within the hub 4 of wheel 1 there is an antifriction bearingassembly outboard of the shoulder 3 and comprising a spherical rollbearing 5, a cylindrical roll bearing 6 and two distance keeping(positioning) rings 7 and 8. The spherical roll bearing is positioned orcentered about in the plane which is perpendicular to the axis and goesthrough the rim of wheel 1 where this contacts the rail. The inner ringsof the bearings 5 and 6 are separated by a ring 7 and the outer rings ofthese bearings by ring 8. The bearings 6 and 5 lie inboard and outboardof the plane through the flange of the wheel, respectively, in the formshown.

To the right in FIG. 1 the bearing is enclosed by a set of labyrinthseal rings 9 and 10, labyrinth seal ring being secured by bolts in amanner not shown to the hub 4 of wheel 1. Labyrinth seal ring 9 restsagainst collar 3 of axle 2. To the left in FIG. 1 the bearing is alsoenclosed by a set of labyrinth seal rings 11 and 12, labyrinth seal ring12 having been slid into the hub 4 from the central side of the axle orshaft. The lubrication of the bearings 5 and 6 is possible through apassage in communication with a lubricating nipple 13, said passageopening between rings 7 and 8. Axle or shaft 2 is extended to have anaxle end 14, on which there is a sleeve 15. The upper structure of therailroad carriage is mounted on said sleeve in such a way that theweight of this upper structure with the load of the car is transmittedthrough sleeve 15 onto axle end 14. This is diagrammatically shown by anarrow P giving the concerning force in FIG. 1. Sleeve 15 is enclosed andkept in position in contact with wheel 1 by means of a pressure platesystem or means l6, 17, 18. This pressure plate system consists of twoplates 16 and 17 and three bolts 18. Pressure plate 16 is in contactwith the edge of sleeve 15 by a collar-shaped edge and is spacedsomewhat from the outboard end of the axle 14, as shown. Moreover plate16 has a protruding part at 19, pointing outwardly and being positionedcentrally of the plate. In contact with this protruding part is apressure plate 17. By means of the set of bolt means 18 this plate 17 isdrawn towards the axle end 14, for which purpose the end face of thisend is provided with screw-threaded holes. Bolts 18 thereto extendthrough holes 20 in pressure plate 16, which holes 20 are of such adiameter that the bolts 18 pass therethrough with considerableclearance.

In FIG. 2 the pressure plate 17 with bolts 18 is shown and it appearstherefrom that these three bolts are positioned on the comers of ageometrical figure being an equilateral triangle symmetrically withrespect to the axis of the system.

Now if the load P is transmitted to sleeve 15 and from this sleeve 15 toaxle end 14, this axle end will bend downwardly under the influencethereof. However, as the sleeve does not extend through the inside ofthe wheel, there will be almost no bending moment in the sleeve aboutthe same axis as the bending moment occuring in the axle 2. As a resultthereof the end face of the axle end 14 and the left end of sleeve 15turn a little with respect to each other so that the heads of the bolts18 will tend to displace mutually to a different extent with respect topressure plate 16. This unequal displacement is taken up in thatpressure plate 17 will tilt about supporting surface 19 with respect topressure plate 16. This tilting will automatically adjust itself in sucha way that the forces in the three bolts 18 will be the same.

If only two bolts 18 would be applied, a free possibility of movement ofthe plates 16 and 17 with respect to each other transversely to theconnecting line of these two bolts would remain. If more than threebolts 18 would be applied, the adjustment of pressure plate 17 withrespect to plate 16 would always be only such that at most in threebolts the tension forces would be substantially the same, although alsoin the remaining bolts the differences in pulling forces would besubstantially less than without a free movability of the two pressureplates 16 and 17 with respect to each other. It is, however, clear thatthe best compensation of the differences in the tensile forces in thebolts will be obtained if three bolts 18 are applied. In that case theplates 16 and 17 will have to make the least possible tilting movementwith respect to each other if the bolts are placed according to the saidpattern of an isosceles triangle.

As will be clear from the above the correction in the bolt forcesobtained by the invention is necessary as a result of the occurence of abending moment in axle end 14. By the positioning of the spherical rollbearing 5 about the plane through the active part of the rim of wheel 1the amount of this bending moment is reduced as far as possible.

We claim:

1. An improved car wheel structure for supporting heavy load, saidstructure being of the type comprising a. a shaft or axle having anoutboard end and a shoulder spaced from and facing said outboard end,

b. an anti-friction bearing assembly supported on said axle outboard ofsaid shoulder,

c. a wheel mounted on said bearing assembly and rotatable thereonrelative to said axle, and

d. pressure plate means secured to the outboard end of said axle forpressing said assembly against said shoulder; wherein the improvementcomprises e. a sleeve mounted on the outboard end of said axle betweensaid pressure plate means and said assembly,

f. a first pressure plate in said pressure plate means and bearingagainst the outboard end of said sleeve and spaced from the end of saidaxle,

g. a second pressure plate in said pressure plate means bearing againstsaid first pressure plate outboard thereof for pressing said firstpressure plate against said sleeve h. one of said pressure plates havinga central protruberance extending toward the other for limiting themutual contact between said pressure plates to the central parts thereofin substantially axial alignment with said axle, and

i. a set of bolt means in said pressure plate means arranged in spacedrelation about said central portion and passing through said first andsecond plates and threadedly engaging in the end of said axle in spacedrelation about its central axis,

j. said bolt means passing through said first plate loosely,

whereby tightening of said bolt means exerts pressure via said secondplate, said protruberance, said first plate, and said sleeve againstsaid assembly, while providing for relative tilting of said first andsecond pressure plates about said protruberance on bending of said axle.

2. An improved structure as claimed in claim 1, wherein said bolt meansare positioned to lie on a circle concentric to the central axis of theaxle.

3. An improved structure as claimed in claim 2, wherein said setconsists of three bolt means equally spaced about said circle.

4. An improved structure as claimed in claim 1, wherein saidanti-friction bearing assembly comprises first and second anti-frictionbearings, the first bearing being a spherical bearing positioned in theplane through the rim of the wheel, and the second being a cylindricalroller bearing at a distance from said first bearing. v v

5. An improved structure as claimed in claim 4, wherein said wheel isflanged and said second and first 5 bearings are positioned inboard andoutboard of the plane through the flange of the wheel, respectively.

1. An improved car wheel structure for supporting heavy load, said structure being of the type comprising a. a shaft or axle having an outboard end and a shoulder spaced from and facing said outboard end, b. an anti-friction bearing assembly supported on said axle outboard of said shoulder, c. a wheel mounted on said bearing assembly and rotatable thereon relative to said axle, and d. pressure plate means secured to the outboard end of said axle for pressing said assembly against said shoulder; wherein the improvement comprises e. a sleeve mounted on the outboard end of said axle between said pressure plate means and said assembly, f. a first pressure plate in said pressure plate means and bearing against the outboard end of said sleeve and spaced from the end of said axle, g. a second pressure plate in said pressure plate means bearing against said first pressure plate outboard thereof for pressing said first pressure plate against said sleeve h. one of said pressure plates having a central protruberance extending toward the other for limiting the mutual contact between said pressure plates to the central parts thereof in substantially axial alignment with said axle, and i. a set of bolt means in said pressure plate means arranged in spaced relation about said central portion and passing through said first and second plates and threadedly engaging in the end of said axle in spaced relation about its central axis, j. said bolt means passing through said first plate loosely, whereby tightening of said bolt means exerts pressure via said second plate, said protruberance, said first plate, and said sleeve against said assembly, while providing for relative tilting of said first and second pressure plates about said protruberance on bending of said axle.
 2. An improved structure as claimed in claim 1, wherein said bolt means are positioned to lie on a circle concentric to the central axis of the axle.
 3. An improved structure as claimed in claim 2, wherein said set consists of three bolt means equally spaced about said circle.
 4. An improved structure as claimed in claim 1, wherein said anti-friction bearing assembly comprises first and second anti-friction bearings, the first bearing being a spherical bearing positioned in the plane through the rim of the wheel, and the second being a cylindrical roller bearing at a distance from said first bearing.
 5. An improved structure as claimed in claim 4, wherein said wheel is flanged and said second and first bearings are positioned inboard and outboard of the plane through the flange of the wheel, respectively. 